Two-dimensional and pulsed Doppler ultrasound techniques were used to examine 87 fetuses between 17 and 41 weeks' gestation in order to compare pulmonary artery and aortic outflow diameters, mean and maximal flow velocities, and transvalve flows. For purposes of analysis, fetuses were divided into two groups: Those less than 31 weeks, and those of 31 weeks or more. Diameters of the pulmonary artery and aortic outflow region increased with advancing gestational age (P <.001), while mean and maximal Doppler flow velocities did not change. Transvalve volume flow increased across both regions (pulmonary artery from 381 ± 12 mL/minute to 530 ± 13 mL/minute and aortic outflow from 286 ± 10 mL/minute to 410 ± 13 mllminute, P <.001) with advancing gestation. Pulmonary artery diameters were larger than aortic outflow diameters in both groups (P <.01), while mean Doppler flow velocities were not significantly different. Maximal Doppler flow velocities were greater in the aorta than in the pulmonary artery (P <.001), and transvalve flow was greater across the pulmonary artery than the aorta in both groups (P <.05, ratio 1.3:l). This work demonstrates differences in fetal pulmonary artery and aortic outflow anatomy and physiology that must be considered in evaluating studies of fetal cardiac physiology.
|Original language||English (US)|
|Number of pages||4|
|Journal||Obstetrics and gynecology|
|State||Published - Feb 1987|
ASJC Scopus subject areas
- Obstetrics and Gynecology